On 08/20/2018 09:00 AM, Grant Taylor via bind-users wrote:
On 08/20/2018 05:23 AM, Tony Finch wrote:
If the local root zone gets corrupted somehow (maliciously or otherwise) the usual setup cannot detect a problem, but it'll cause DNSSEC validation failures downstream. The normal resolver / validator algorithm is more robust.

The new mirror zone code validates the root zone before installing it, which at least allows it to detect a problem; I have not examined it closely enough to see how hard it tries to recover by xfering the zone from a different root server, or if it just falls back to normal resolution.

Thank you for that explanation.  It explains why it's potentially dangerous to blindly slave the root zone for general use by clients on a local recursive resolver.

No, it doesn't do that at all. It may be true that the new mirror zone code does awesome things to make sure that the slaved zone is identical to the master's, I don't know, I haven't seen it.

But that doesn't mean that slaving a zone, any zone, including the root, is "dangerous." If slaving zones is dangerous, the DNS is way more fragile than it already is.

The DNSSEC validation errors that Tony references are self-healing, in that if the validating resolver stops validating things, the operator is hopefully going to notice that, and take steps to fix it. And I have always said that you should not be slaving the root unless you already have a good mechanism for making sure that said slaving isn't failing. (In other words, don't go into this, or any other configuration blind.)

I am certainly open to the new mirror zone software doing awesome things, don't get me wrong. But don't call something "dangerous" that lots of people have already been using successfully for over 15 years.
_______________________________________________
Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe 
from this list

bind-users mailing list
bind-users@lists.isc.org
https://lists.isc.org/mailman/listinfo/bind-users

Reply via email to